Chime modification is not very difficult. You will need to know your installer code for the system to get into programming. The factory default is 5555.
First you need to enter keypad programming.
Enter *8 5555
Display should read "Select (000) - Zone Labels"
At this point you will have to enter the section of programming for the keypad you're working with. Keypad programming sections are 861-876. Section 861 corresponds to keypad 1 and so on.
After entering the keypad number you will next enter the zone number you want to change the chime for. You'll do this by taking the zone number and adding 100 to it. So if you wanted to change zone one's chime you would enter 101.
Select the two digit number of the option you want. After entering the two digit option it will kick you back out to where you can enter the next zone to work with.
Repeat the above for any other zones you wish to change. ### to exit.